Modifying the NLCD with current observations

[jmszy]

Hi there,
I am doing a research on InVest and I am currently trying to use NLCD dataset which is lastly updated 2019. If I want to make some changes to part of the data to have the 2023 version of it e.g. a small area that is interesting, what’s the correct way to do it, is it to change the attribute table or modify the c_below and c_above value for each time? Thanks!

[swolny]

Hi @jmszy -

Do you want to change the NLCD raster data itself to be updated to 2023? Or do you want to use the 2019 raster data and assign carbon pool values to it that are different between 2019 and 2023? Or do you have something else in mind?

~ Stacie

[jmszy]

Hi there
I have tried to change the NLCD data via attribute table, but that changes the whole land cover type so it doesn’t actually work, is there any way to modify the raster to make it look like 2023 or can I fiddle with the carbon pool and the invest model to make up the 2023 carbon value? Thanks！

[swolny]

I’m guessing that you want to make changes to specific pixels in the NLCD raster that have changed between 2019 and 2023. For example, perhaps there’s a certain area that was agriculture in 2019, but has since been restored to natural grassland. To do this, you’ll need to use your GIS skills to modify the NLCD raster, changing those specific agriculture pixels to have the land use code of grassland. Then the model will match the carbon values for grassland to these pixels, and you don’t necessarily need to change the carbon pool table.

If you want to add a new land cover class that’s not in the 2019 NLCD, then you’ll also need to add a new row to the carbon pool table, and specify the carbon values for that new class.

~ Stacie